(1) Field of the Invention
The present invention relates to bypass line assembly incorporating a manual throttle valve modified to contain a hole extending through the throttle valve ball to reduce the incidence of overpressure failure.
(2) Description of Related Art
It is common in the art of refrigeration units to employ water cooled chillers which have a hot gas bypass arrangement. The use of such a hot gas bypass arrangement allows for the stable operation of the water cooled chillers at low loads. The hot gas bypass valve is activated by the chiller control system to open when the load falls below a certain predefined level. As such, the hot gas bypass valve may either be in an “on” or an “off” position. It is sometimes preferable, however, to achieve finer control over the operation of the hot gas bypass valve. To achieve such fine control, a manual ball valve is used in series with the hot gas bypass valve. During shutdown of the assembly, liquid can get trapped between the ball valve and the hot gas bypass valve. In the event that both the manual ball valve and the hot gas bypass valve are shutoff and the pipe adjoining the two valves is subject to heating for example from the ambient air, high pressure can result and the assembly can experience failure. Specifically, the assembly is prone to failures due to excessive pressure in the line connecting the hot gas bypass valve to the manual ball valve.
What is therefore needed is a method for relieving the pressure which may develop between the manual ball valve and the hot gas bypass valve which does not sacrifice the low load requirement.